UJOTYP-51: Variant for NONE type
- add function "ujot_variant_new_none"
- respect NONE type during serialization
- adapt to changed function "ujo_element_get_type" to get the "is_null_type" flag
- fix minor bug in function "ujot_variant_new_binary"
- enhance structure generator/verifier by NONE type
- extend test structure by NONE and NULL types
- remove constants "UJOT_UJO_TYPE_MASK" and "UJOT_UJO_TYPE_NULL" (no longer needed)
Edited by Björn Latte